Method of casting separable fastener stringers



Jan. 31,, 195%!) 1 H. MORIN z9496vfi3w METHOD OF CASTING SEPARABLEFASTENER STRINGERS Original Filed May 23, 1942 INVENTOR [00/5 bf flaw/vBY 7 W ATTO NEY Patented Jan. 31, 1950 iJlTED 'iA'ilES PATENT FFIQMETHOD OF CASTING SEPARABLE FASTENER STRINGERS ceased Qriginaiapplication May 23, 1942, Serial No. 444,191. Divided and thisapplication August 22, 1945, Serial No. 612,091

1 Claim. 1

This invention relates to separable fasteners employing stringersadapted to be coupled and uncoupled. More particularly, the inventionrelates to a method of simultaneously casting two or more links orscoops of a fastener of this kind upon a tape or other mounting and acore element and further in stripping or otherwise removing the coreelement from the castings, The novel features of the invention will bebest understood from the following description when taken together withthe accompanying drawing, in which certain embodiments of the inventionare disclosed, and in which the separate parts are designated bysuitable reference characters in each of the views; and in which:

Fig. 1 is a diagrammatic sectional view illustrating the method offorming a pair of links or scoops on a mounting member.

Fig. 2 is a perspective view of two of the scoops shown in Fig, 1indicating the core removed and showing the form of gate employed.

Fig. 3 is a side and sectional view of a part of a stringer showinganother type of link or scoop and indicating the method of producing thesame.

Fig. 4 is a view similar to Fig. 3 showing another form of link orscoop.

Fig. 5 is a diagrammatic view illustrating the type of gate employed incasting end links.

Fig. 6 is a view similar to Fig. 5 illustrating the method of casting amultiplicity of links; and

Fig. '7 is a diagrammatic View showing the spacing between successivegroups of castings.

This application constitutes a division of my prior application, SerialNo. l4=l,l91 filed May 23, 1942 and issued January 8, 1946, as PatentNumber 2,392,684.

In the die casting of links or scoops of sepa rable fasteners of thewell known kind employing stringers and a slider movable along thestringers to couple and uncouple the same, it has been the commonpractice to cast the links or scoops one at a time and this has beenessential in order to form the male and female interlocking portions onthe scoops and particularly the undercut female portion, Many attemptshave been made to die cast a multiplicit of links or scoops in formingcomplete stringer lengths but such attempts have been impractical andinoperative or have presented such outstanding difficulties as to resultin the production of stringers which were not commercially practical.

After lon and careful study and experimentation, the desired objective,namely castin of .2 two or more similar links or scoops, has beenaccomplished in a commercially practical manner by utilizing a commoncore element to form the undercut or female coupling portion of all ofthe links and either stripping this core element from each group oflinks and utilizing the same for casting the next successive group, orin using a separate core element for each group of castings andafterwards removing the same from the links or scoops, as more fullyherein after set forth.

In order to diagrammatically illustrate the general method employed informing castings of the kind under consideration, I have indicated inFig. 1 one-half of the die i a in which is formed one-half of the twosimilar cavities or impressions i l shaped to form a pair of links it aswell as the gate 13 through which metal from an injector nozzle M ispressure injected into the cavities H. The ends are also provided withrecesses or cavities l5 for the reception of the mounting member or tapeit and with another cavity I! for the reception of the core element 18.

The method of forming the pairs of castings I2 will be readilyunderstood from the foregoing and the following description. When bothparts of the die II] are in open position, the mounting member 16 isarranged between adjacent surfaces thereof, as is also the core elementiii. The die parts are then brought into firm engagement with each otherand at this moment heated casting material, which may be metallic orplastic, is pressure injected through the nozzle M, in forming thecastings !2 simultaneously on the mounting member 46 and around the coreelement i8 and filling the gate it. The dies are then opened; the coreelement 18 and tape [6 are moved downwardly bringing the first cast pairof links I 2 into the position indicated at (9 in Fig. 1, after whichthe core element It is stripped from the castings, moved up to itsoriginal starting position, after which the dies are again closed andthe above operation repeated. In the stripping operation, the uppermostlink 12 of the first cast pair of links is arranged adjacent the lowersurface- 20 of the dies and this serves as means to properly space thesuccessive pairs of links on the mounting member [6. It will appear thatthe gate passage has an initial opening 2! which branches upwardly anddownwardly as indicated at 22 and the latter terminates in yokes 23which encircle half of the core element 13, note Fig. 2 of the drawing.

The above operation of casting pairs of links or scoops on the mountingmember i5 repeated until such time as a predetermined series of linkshave been formed on the mounting member, after which the mounting membermay be independently fed to produce a wide spacing thereon to spacesuccessive series of links in forming what is ten ied stringer or chainlengths as is known in the art.

Each link [2 is of the same construction and comprises upwardly anddownwardly extending triangular projections 2e adapted to entercorresponding recesses in links of an opposed stringer when thestringers are coupled together. On the outer surface of each link, thecore element it forms an arch-shaped recess 26 which will engagecorrespondingly formed projecting elements 2i arranged in the recessedportions 25 of the opposed stringer links. In other words, the links orscoops 12 are what I term double acting type, both upper and lowersurfaces being of identical construction which permits coupling of thelinks by a slider movable in both directions on the stringers, In otherwords, it is immaterial which way the slider is positioned on thestringer to produce the coupling engagement and, of course, the same istrue for the uncoupling of the stringers. This construction furtheradapts the stringers for the use of two sliders operating on a singlepair of stringers or chains.

At this point, it is well to bring out the distinct advancement in theart which is accomplished by the conception of the method to produce letus say, for example, two links or scoops in one casting operation.Heretofore, individually cast links or scoops have been commerciallyproduced at the rate of approximately 350 castings a minute, althoughhigher speed castings have also been produced. But on the basis of 350per minute, it will readily appear that by simultaneously casting twolinks or scoops in each casting operation, the production has beenincreased one hundred per cent. In like manner, by casting three linksor scoops at one time this production will be increased two hundred percent. From a practical standpoint the size of the link or scoop willgovern to some degree the practicability in casting, according to theteachings in Fig. 1 of the drawing, the predetermined number of links.For example, with the smaller size links a larger number of links may beformed in each casting operation, by this I mean, in the process where acomplete stringer length or chain is made up of a series of multiplecastings.

Where short stringer lengths are required, all of the links of thecomplete stringer length may be cast in one operation, as morespecifically described hereinafter. On the other hand, where extremelylong stringers are required, these long lengths may be cast in multiplegroups, and where the groups are comparatively long, a single coreelement may be used for all groups on each stringer length.

With the construction shown in Figs. 1 and 2, the core element 58 isarranged upon the outer surface of the links or scoops to form theresulting recesses or undercut sockets 26. Instead of this method ofprocedure, I have illustrated in Fig. 3 of the drawing another methodwhich comprises arranging a core element 28 inwardly of the outersurfaces 29 of a pair of links or scoops 3G and centrally of theprojecting portions 3i which are equivalent to the portions 24. Withthis type of construction, sockets or apertures 32 are formed throughthe links or scoops which are 4 adapted to receive projecting couplings33. centrally of the recess portions 34 thereof. In other words, withthis type of link the apertures or sockets 32 receive the projections 33of the links or scoops of the opposed stringer when the stringers arecoupled together, in the same manner as the engagement of theprojections 2'! with the recesses 26. With this method of procedure, thegate 35 simply has two extensions 35 which are disposed on the surfaces2% of the links. At this time, it will be well to mention that the gatesare removed from the links in the production of the resulting fastenerstringers in what is generally known as the trimming operation.

In Fig. 4 of the drawing is shown another method of procedure whereinthe core element 31 forms in the links 38 apertures 39 which arearranged inwardly of projecting portions 4!) disposed on upper and lowersurfaces of the links or scoops outwardly of the apertures 39. With thisconstruction, it will be apparent that the projections ii! of the linksor scoops of one stringer will engage the apertures or sockets 3Q of thelinks or scoops of the opposed stringer. The gate M of Fig. 4 is thesame as the gate Eli of Fig. 3.

From a comparative consideration. of the structures, as seen in Figs. 1,3 and 4, it will be apparent that in Fig. l the core element is disposedoutwardly of the projecting elements of the scoops. In Fig. 3 it isdisposed centrally of the projecting elements of the scoops; whereas inFig. 4 it is arranged inwardly of the projecting elements. Theseillustrations are simply to show general adaptations of the inventionwithout limitation to the particular structure of each link or scoop.

In Fig. 5 of the drawing, I have diagrammatically illustrated thegeneral form of gate which may be utilized in simultaneously castingthree links or scoops. In this figure, :2 represents the gate which hasthree branches 53 leading to the resulting three castings, partiallyindicated at 44, these castings being all formed on a single coreelement 45. It will thus appear that if four castings are formed, fourbranches will be provided in the gate instead of three.

In Fig. 6 of the drawing, I have diagrammatically illustrated a shortsection of a complete gate arrangement which would be utilized informing a large number of links or scoops or a complete stringer length.The gate in this construction will have an admission portion 45 openinginto a large distributing portion 41 from which there will be amultiplicity of independent branches 48 leading to the individual linksor scoops 49 all arranged on a core element 50.

In forming complete stringer lengths which are comparatively short, itwould be desirable to form these complete stringer lengths on individualcore elements 5! as is indicated in Fig. 7 of the drawing, the elementsbeing spaced apart at the wide spacing portions 52 of the tape ormounting member which subdivide the complete stringer lengths from eachother. For example, the stringer length 53. diagrammatically shown inFig. 'l, is spaced from the end stringer lengths as, 55. Where very longstringer lengths are required, a long strand may be used as the coreelement 5! and this strand will be continuous through the multiplegroups of castings to form the complete stringer length and if desiredmay continue or bridge across the spacing between the long stringerlengths. With this type of construction, it would be desirable to employa core element havin flexible characteristics.

In some instances and particularly where the core element is used as ameans for feedin groups of links, for example, as is referred to in Fig.1 of the drawing, it is preferred that the core element comprise arelatively rigid body prefcrably of metal. In all other instances,however, the core element may comprise, for example, an endless strandof wire, along which may be formed the successive group castings or thiscore element may comprise a flexible and yet substantially firm strandof any type or kind so long as it is possible to strip or otherwiseremove the core element from the resulting castings. In some instances avery low melting point metal may be used and in other instancesmaterials capable of being chemically or otherwise removed would also bepractical. The only precaution that is required is to use a strand-likeelement for the core which will have a surface which will provide freeremoval of the element from the resulting casting without marring orobstructing the casting.

In forming complete stringer lengths on a long mounting member, it willbe understood that means will be provided to feed the mounting member tosuccessively bring spaced sections thereon in position between themultiple impression dies employed for forming on the mounting membersections of the complete stringer length. On the other hand, where thecomplete lengths are made from series of group castings, the mountingmember will be fed to bring the groups of castings into proper spacedrelationship to each other so that adjacent links of each group, in acomplete stringer length, will be properly spaced with respect to eachother in the same manner as taught in the series of links formed asillustrated in Fig. l of the drawing.

It will also be apparent that the gate portions of the resultingcastings which are removed by trimming or other operations are reheatedor melted so that these gate portions do not amount to waste. Therefore,the size of these gate portions is of no particular consequence from astandpoint of production cost.

In all instances, the dies employed will be cooled in accordance withknown methods and no detail showing is required in this respect as it isquite old in the art of forming pressure die castings.

From the foregoing, it will be apparent that my improved method, inaddition to materially speeding up the production of products of thekind under consideration, in a more specific sense may be said tocomprise the steps of simultaneously forming two or more castings by theuse of a single core element. The socket or female portions of the linksor scoops serve for the reception of projecting coupling elements whichretain the coupled links or scoops against separation. Furthermore, twoor more identical link or scoop structures are formed.

It is also preferred that each part of the die include an auxiliarystripping element 56, as seen in Fig. 1, which will engage the lowerlink of the pair of links in removing the core. In stripping long coreelements from a multiplicity of castings, a suitable jig or fixture willbe used to receive the links or scoops so that all of the links orscoops will be supported in this pulling or stripping operation. Instripping the core element l8, as taught in Fig. 1, the operation isperformed while the dies are in a partially open position and thecavities of the dies support the links or scoops in this operation. Inother words, after the dies are first opened, to move said cast linksand tape to the position IS, the dies are partially closed.

In casting a plurality of links or scoops, it is, of course, notessential that these scoops be formed directly upon a tape or othermounting and may be simply cast on the long core element which willmaintain the castings in desired spaced relationship to each other andthe castings thus formed and arranged can be applied to any suitablemounting. It will be understood that a core element will be provided inthe dies for forming the forked or U-shaped ends of the links or scoopsto receive the mounting. In employing core pins or elements for themultiplicity of cast links or scoops having coatings thereon tofacilitate removal, coatings such as graphite may also be used.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent is:

The method of producing separable fasteners employing stringers withscoops spaced longitudinally thereof, which comprises simultaneously diecasting in a pair of dies a plurality of complete scoops, each scoopincluding a tape gripping portion and a coupling portion, in spacedrelation on a preformed core element; removing the core elementincluding the scoops thereon from the dies; directly applying saidscoops to a tape by attaching the tape gripping portion of each scoopdirectly to the edge of said tape; removing said core element from allof the scoops, and then trimming all of said scoops.

LOUIS H. MORIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,307,410 Kuna Jan. 5, 1943FOREIGN PATENTS Number Country Date 391,146 Great Britain Apr. 18, 1933

